This invention relates to spinning devices and in particular to ring spinning devices, in which the produced yarn is wound in the form of packages onto generally conical tubes which form the package core.
The yarn packages are completed at a predetermined wound length and are then fed to the next process, generally winding, in which the produced yarn is rewound to remove defects and improve product quality, and to produce larger-sized bobbins, the empty tubes being returned to the spinning stage for their reuse.
The empty tubes and produced packages are conveyed within the spinning machine by conveyors currently known as doffing belts, on which erect positioning pegs are provided for the tubes and packages, these pegs being either fixed to the belt surface in a perpendicular position or based on discs disposed on the belt. The spinning machine doffing members deposit the finished packages to be removed from the spinning machine onto the doffing belt and withdraw empty tubes from other positions of the belt to reposition them in the spinning stations to again wind new yarn onto them to form new packages.
European patent application No. 88200602 of the present applicant describes gripping members for doffing the packages and tubes. At one end of the belt there is an empty tube loading station in which the belt presents the pegs for filling with the tubes to be returned to the spinning stations for the next doffing operation. These tubes may be either new tubes taken from the tube store, or tubes which were emptied during the winding stage following the spinning stage, and recycled.
As spinning machines of recent design comprise a large number of spinning stations, perhaps one thousand or more, and considering that the packages are doffed either all together or in groups at the same moment, the doffing operation may require the unloading of one thousand or more packages simultaneously and the repositioning of one thousand or more empty tubes, which then have to be reinstated within the required time on the doffing belt.